Suspended furnace arch



Jan. 5, 1954 R. A. BANQK SUSPENDED FURNACE ARCH 2 Sheets-Sheet 1 Filed; Aug. 12, 1950 m. Q/ r a Jan. 5, 1954 A, A CK 2,664,837

SUSPENDED FURNACE ARCH Filed Aug. 12, 1950 2 Sheets-Sheet 2 IN V EN TOR.

fiaierf Hid/76% B Y Patented Jan. 5, 1954 SUSPENDED FURNACE ARCH Robert A. Banck, Detroit, Mich., assignor to Bigelow-Liptak Corporation, Detroit, Mich., a

corporation of Michigan Application August 12, 1950, Serial No. 179,047

2 Claims.

This invention relates to soaking pits, heavy duty furnaces, and heating or combustion charm bers in general, and in particular refers to their covers, roofs, or arches.

In installations of the type indicated, the covers or roofs are constructed of individual refractory bricks or tiles that are suspendedby suitable means in such relationship to each other as to form a ceiling for the combustion chamber. The present invention provides a, construction of tile and suspending means that has several desirable features and advantages from the standpoint of function and performance as well as erection and. repair costs.

One of the desirable features of the construction described herein is that localized areas of tiles may be readily removed and replaced without disturbing adjacent tiles or their suspending means. This greatly facilitates repairs since in many cases only isolated areas become damaged while the remainder of the roof is in good condition.

Another feature of the invention resides in construction of the tiles and suspending means which is such that special contours may be obtained and yet cracks and crevices through which air could readily pass are eliminated and the tiles remain in close contact throughout the range of temperatures to which they are subjected in service. This improves combustion efficiency in the furnace and also tends to protect the supporting structure from heat escaping by convection.

Another feature of the invention enables a reducticn in heat loss by radiation without inviting failure of the metallic arch or roof support. This results from the use of novel hangers as the suspending means for the tiles which are of a shape that can be readily and economically made from alloy steels capable of withstanding the high temperatures over the furnace roof. Insulation to reduce heat losses can then be laid over the roof without danger of weakening the hangers. In some cases, the insulation also permits smaller tile to be used thus obtaining the advantages of lower material and erection costs as well as greater resistance to spalling.

A feature of practical importance is that certain of the metallic tile suspending elements are exposed to cooling air which by reducing operating temperatures increases the effective strength of the elements and, in some cases, make it possible to eliminate much of the steel structure conventionally used.

A further feature of the invention consists in the support of more than one tile on each hanger. This reduces materially the number of hangers which, in turn, reduces cost and the weight suspended on the supporting structure and also facilitates installation and repair.

Also an important feature is the simplicity of the design of the suspending means and the tile which enables them to be manufactured at lower cost, it being possible to manufacture certain elements of the suspending means from standard structural materials.

Other features of the invention will appear upon consideration of the accompanying drawings, in which: 1

Figure 1 is an isometric view with parts removed and broken away of a roof embodying the invention;

Fig. 2 is a section through a set of tiles supported on one form of suspending means of this invention;

Fig. 3 is an enlarged View of the hanger bar construction within the circle 3 on Fig. 1;

Fig. 4 is an enlarged cross section taken on line 4-4 of Fig. 2;

Fig. 5 is an isometric view of a modified form of the invention;

Fig. 6 is a side elevation, broken away, of an" other modification of the invention; and

Fig. 7 is an elevation taken from the left of Fig 6.

The roof fragmentarily shown in Fig. 1 is intended to typify the various installations which may benefit by the present invention. The roof truss or supporting structure comprised of beams I may obviously be of various constructions and be supported itself in any suitable manner, for

example, the beams may rest on the side walls of the furnace or other structure.

In accordance with the invention, the ceiling surface for the chamber covered by the roof is provided by the bottoms of two dilferent types of blocks of suitable refractory material, identified by the reference numerals 3 and 5. These blocks, referred to herein as tiles or bricks, are carried by lower ends of hangers l which, in turn, are supported on hanger bars 9. The hanger bars 9 extend transversely to the beams l and are shiftably suspended on them, this being accomplished by U shaped anchor bolts 5 l on the beams I that extend through slots [3 in vertical flanges it formed integrally on the bars 9. Layers of insulation Il may be placed over the top ends of the tiles or bricks 3 and 5 and around the hangers l and below bars 8.

Each hanger lcarries the weight of two tiles 3 and one tile 5. The tiles 3 are directly supported on the bottom of the hanger while the tiles 5 are directly supported on the two adjacent tiles 3 as readily observed in Fig. 1. The tiles 3 are basically similar in shape to a rectangular parallelopiped and their sides which are parallel to the direction of the bars 9 will be referred to by reference numerals I9 and 2 l, and their sides which are transverse to the bars 9 will be referred to by numerals 23 and 25. The sides Zl are offset inwardly adjacent the tops of the tiles 3 as shown at 2i and the bottoms of the ofiset portions 27 are undercut as shown at 29, it being observed that the top surface 3! of the undercut 29 is inclined downwardly in the direction of the side H. The tops of sides l9 of the tiles 3 are offset inwardly as 3 shown at 33 to provide upwardly'presenting shoulders 35 for supporting the tiles 5. The sides 23 and 25 are provided, respectively, with complementary, transverse, integral tongues and grooves or keys 35 and keyways 31 Ithat :areiofiset with respect to the general planes. of thesesides. The tongues or keys 33 fitjin the .grooveszor keyways 31 of the adjacent tiles 3 and serve to interlock the tiles as well as to substantially interfere with air or gas flow through :the assembled 'roof. It will be observed in Fig. 1 that in the adjacent rows of tiles 3 that are suspended from the same hanger bar 8, the tiles are preferably facing in opposite directions, thus servingto improve the structural integrity of the roof and also eliminating the necessity for making left hand and right hand tiles.

' In order to support the pairs of tiles 3, each hanger 'I has fmt or flanges 39 extending upwardly and outwardly from the bottom thereof on an angle that is preferably the same as'that of the tile surfaces 3! which rest on them. It will be seen that the reaction forces of each flange 39 to the gravity load imposed ona hanger l by a pair of tiles 3 have horizontal components, due to the inclination of surface 3% and flange'39, which force the tiles 3 together and hold them in intimate contact regardless-of expansion and contraction during operation of the furnace. "While this tends to prevent leakage of .air along the juxtaposed sides .2 I these sides are-preferably also complementarily recessed to provide grooves M for mortar '43. The mortar bodies 3 in the grooves 4| provide offsets to air or gas flow between the ,tiles 3 of a pair and thereby render it unnecessary to make left and right hand tiles in a pair.

-The shanks or hangers I extend upwardly from the flanges '39 to terminate in heads 55 that are .mounted insideo'f the hanger bars 9. 'The heads 445 have downwardly presenting shoulders 4? that are wider than the width of the'lengthwise slot 49 in the bar 9 through which the shanks of ;the hangers I extend and which rest on the surfaces 5| of the bar walls adjacent the slot whereby the bars support the hangers"? and the tiles. The shoulders d! are rounded and preferably cylindrical as are the wall surfaces 51 on which they rest. As evident from Figs. 2 and l, by rounding the shoulders 41, the hangers 1 can rock somewhat on the bar 9 to permit adjustment of the tiles such as may result from the influence of. the reaction forces of feet 35 or thermal forces. If the shoulders 4i and surfaces 5! are cylindrical, as illustrated, this rocking is permitted only .in the plane of the drawing but not in the plane of the bar inasmuch as the. engaging su'rfacesare flat with respect to pivotal movement aboutan axis transverse to the .bar 9. (Fig. 4). .This featureprevents accidental twistingof thehangers 1 .inthe .bars and this is important because theheadsllfi are of less thickness than the width. of the slot 49. .However, due to the fact. that .the headsliB may be removed through .the slotliil, eachhanger I may be dropped from .the bar .9 by .angularly turning it 90 degreesabout the axis of. its shank and thenaxially translatingitdownwardly. angular-movement of. the hanger l takesplace, ordinarily, relative to the tiles .3 and is accomplished by lifting the tiles from underneath. so that the flanges 39 contact the bottom surfaces of undercuts 29 and are thus free to rotate relative to inclined surfaces-3i. This contactand .lif-tingalso forces the head shouldersdl off-their seats 5|.

It willzbe recognized that this simple mode of connection and disconnection makes it possible for but one hanger 7 at a time to be removed from "the bar 9 without disturbing adjacent hangers.

[formed at the ends of the bar surfaces 5| to prevent the hangers i from sliding out of the bars 3.

It will also be recognized that the hangers T are of .ashape that may be readily cast or fabricated from alloy steel or from cast iron which maintains its strength-"at elevated temperatures. This shape is also such that there are no areas of excessive stress concentration so that the hangers l are very eiiicient and thus of a minimum weight. These factors make it a practical possibility to also add the weight of the insulating layers I? to 'thehangers l; for the purpose of re- "ducing radiation losses, without inviting failures "of the hangers due to overheating and without unduly increasing the size and cost of the suspending means. The use of insulation fi' may also make'it possible some smaller tiles 3 and 5 than in the conventional suspended wall. The smaller tiles are desirable because of greater resistance to spalling, lower material costs, and lower erection costs.

The foregoing description has shown how the tiles 3 are supported by hangers l on the bars 9. If desired, these tiles may be used exclusively or with intermediate rows of standard bricks which rest on shoulders 35. However, it is preferred to'use tiles5 which, as evident from Fig. 1, are directly supported on the tiles 3 and thus carried by hangers l and bars 9. A row of tiles 5 is supported between each pair of hanger bars 9 on the tiles 3. The tiles 5 are basically rectangular parallelopipeds but have flanges '55 at the top thereof which extend transversely to the bars .to fit in offsets 33in the -ti'lesii and to provide downwardly presenting surfaces 5'! that rest'upon the surfaces ,35 of the tiles 3 whereby the tiles 5 .are suspended from the hanger bars '9. The offsets 33 and flanges 55 obstruct gas passage between the faces of the tiles thatare parallel to the bars 9. Gas flow through the mutually contacting faces of the tiles 5 thatare transverse to the bars 9 .is obstructed vby'keys 59 and keyways that are similar to keys 35 and keyways 3?.

It is apparent that by lifting a tile 5 from its seat on'the'shoulders 35 that the adjacent tilesfi" may be readily replaced. 'The'use of intermediate'tiles 5, ofc'ourse, increases the spacing of hanger bars 9 and reduces thenumber of hangers I thus lessening the cost of the installation.

"The hanger bar .9 may he of other forms than thatillustrated in Figs. 1+4 which may be readily made from standard structural elements. For example, in Fig.5, afhanger bar 55 is illustrated that is constructed from standard cylindrical tubingv thathas a slotifiii cut in the bottom to receive theshanks of hangers "l. Suitable'fiahges 619 are welded to the ltopof the tubing so that the bar may be suspended on beams i .by bolts H.

In.Figs. 6 and .7, thehanger .bar H is conistructedof two. angle bars .13 and 15 that are arranged .so that the. angles :open toward each other. "The top edges .of-the. bars E3 and iii are interconnected to .form. a structural unit by flanges .11 which are welded .thereto and, if desired, the flanges .ll maybe extended downwardly and welded 'to .the bottom edges to increase the strength of the assembly. The flanges I1 serve to separate the lower edges of the bars and to provide a slot 19 for the hanger shanks. They also have slots 8| therein to receive bolts I I whereby the bar H may be shiftably suspended from beam I. It will be observed that the bar H is provided at its end with an angle shaped foot 83 that is welded thereto and rests on a ledge 85 of the furnace wall 81. The foot 83 thus serves as an alternate or an additional means of supporting the bar and being obviously applicable to the other forms of hanger bar illustrated herein. It will be observed that in all forms the hanger bars are above the insulation I! and thus in contact with cool air so that their temperature is low and strength high thus making it possible to eliminate the beams l, in some cases, without inviting failure of the roof, by supporting the bars on ledge 85.

These and other benefits flow from various structural features of the present structure and it is evident that useful improvements can still be obtained by modifying the construction in certain respects or by employing less than all of the features disclosed herein. These changes I will be apparent to those in the art and are within the spirit and scope of the invention.

What is claimed is:

1. In a roof construction, the combination of a plurality of parallel support bars, pairs of tile beneath the bars and extending parallel thereto to form pairs of rows of tile beneath each bar, a common hanger for each pair of tiles, said bars having openings in the bottoms thereof and upwardly presenting surfaces on opposite transverse sides of the openings that are inclined upwardly and outwardly from said openings, said hangers extending upwardly through said openings and having shouldered heads formed on inclines similar to that of said surfaces, said shouldered heads resting on said surfaces and being in one horizontal direction of greater transverse width than the opening in the bars but of less transverse width than the interiors of the bars, and being in another horizontal direction of narrower transverse width than the openings in the bars so that the hangers may be turned and passed through the openings to disconnect them from the bars, said hangers having shank portions extending downwardly from the shouldered heads through the openings in the bars and being of less thickness than the openings in all transverse dimensions, the tiles in said pairs being of substantially identical shape but having the sides transverse to said bar facing in opposite directions, one of the tile sides transverse to the bar having a keyway formed therein and the opposite side having a key formed thereon adapted to fit in said keyway so that the key on one tile is fitted in the keyway of an adjacent tile, the outer top corners of said tiles, with respect to said bars, being cut out to provide 01?- sets having upwardly presenting shoulders, and tiles intermediate adjacent bars having downwardly presenting shoulders resting on said upwardly presenting shoulders so that the tiles are wholly supported thereon, said intermediate tiles having complemental keys and keyways formed therein on opposite sides transverse to said bars so that the keys and keyways on adjacent intermediate tiles are interlocked, the tiles in said pairs contacting each other along the lower portion of a vertical face on each tile, the upper portions of said vertical faces being spaced inwardly from the lower portions, each of the tiles amiss? 6 in said pairs having undercut faces upwardly and outwardly inclined from said upper portions of the vertical faces, said shank portions of the hangers extending downwardly between said upper portions and being spaced substantially therefrom, and flanges on the lower end of said shank portions extending outwardly and inclined upwardly from the sides of the hanger in the same vertical plane as the maximum dimension of the hanger head, said flanges engaging said undercut faces so that the reaction forces thereof urge the tiles in each pair toward their contacting vertical faces.

2. In a roof construction, a plurality of parallel hollow hanger bars having openings in the bottoms thereof extending longitudinally of the bars and upwardly presenting internal surfaces on opposite transverse sides of the openings extending upwardly and outwardly on an incline away from the openings, a plurality of hangers suspended from said bars and having heads resting inside said bars on said surfaces, said heads being provided with surface engaging shoulders formed on an incline corresponding to the incline of said surfaces, there being linear engagement of substantial length between said shoulders and surfaces in a direction parallel to the length of the bars, said shoulders being in one horizontal direction of greater transverse width than the opening in the bars but of less transverse width than the interiors of the bars, and being in another horizontal direction of narrower transverse width than the openings in the bars, said hangers being provided with shank portions extending downwardly from the heads through the openings in the bars and which are of less thickness than said openings in all transverse dimensions, said shank portions having transverse feet on the bottom thereof extending outwardly from the sides of the hanger in the same vertical plane as the maximum dimension of the head shoulders, a pair of tiles supported on each of the hangers, there being one tile on each of said feet, the tiles in a pair contacting each other along the lower portion of a vertical face on each tile, the upper portions of the vertical faces being spaced inwardly from the lower portions and having said shank portions extending therebetween and spaced therefrom, each of said tiles having undercut faces upwardly and inwardly inclined from said upper portions of the vertical faces, the inner ends of said feet being spaced inwardly of the outer ends of said undercut faces, and the outwardly extending portions of said feet being inclined upwardly from said shank portions and engaging said undercut faces whereby the tiles on each hanger are urged into contact with each other along the lower portions of said vertical faces by reason of the operation of gravitation.

ROBERT A. BANCK.

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